Hi everyone
I'm in the process of resolving a similar dispute with o2, I had a contract with them from Dec 2005 to Dec 2006, and in Dec 2008 they added a default to my credit file dated aug 2007 for £12.00!! I phoned them and they told me the only outstanding amount they had on their files was £12.00 that they owed to me. Now I have to wait 30 days to even see if they remove the default from my file, but I will be taking it further if not. Watch this space!!